textproduct: Rapid City

KEY MESSAGES

- Unsettled weather pattern continues with daily chances of showers and thunderstorms throughout this coming week.

- Severe weather risk will return Tuesday with damaging winds and large hail possible.

- Temperatures this week will start off cooler when compared to the end of the week into next weekend. And beyond that, the CPC is giving the CWA a Slight Risk of Extreme Heat.

UPDATE

Issued at 933 PM MDT Sun May 31 2026

Looking ahead to this week, westerly flow in the upper levels will keep the unsettled and active weather in place over the CWA. Tomorrow's thunderstorm chances will likely drift in from the SW. Tuesday, a couple short waves look to track over the area, which would bring better chances for severe weather. The rest of the week continues the near daily chances for storms.

Late this week into next week, summer-like hot weather is becoming a stronger possibility. From the CPC, model guidance solutions for the 500mb height anomalies bring amplified ridging over the Upper Mississippi Valley. This pattern would give the area above normal temps with daily highs well into the 80s to 90s. The GEFS keeps the pattern around for another week, keeping the hot temps in place, while the EURO breaks the ridge down, allowing for daily highs to cool a bit. Stay tuned.

DISCUSSION

(This Evening Through Sunday) Issued at 157 PM MDT Sun May 31 2026

An area of low pressure just to our west will support additional rounds of isolated to scattered showers and thunderstorms today and Monday. Today, cells are especially firing over the Black Hills corridor (although a few cells have been noted in northeastern Wyoming too) and will push east with time. Today's environment features modest CAPE, but very little wind shear, so the severe weather threat seems very limited/isolated and brief in duration with a "pulse" storm mode. It is worth noting that any storms that can track east off the terrain into the South Dakota plains will have access to the best instability and sfc moisture per mesoanalysis and short-term model projections, yet the lack of shear will tend to limit storm organization and longevity. Monday, wind shear increases, but instability remains modest, so the overall severe threat remains low/isolated with perhaps gusty winds or hail on a few of the stronger cells. Northeast Wyoming, the Black Hills, and adjacent South Dakota plains will again be favored for isolated to scattered activity. High temperatures both days will generally top out in the 70s, with some 80s possible across our southern South Dakota counties.

Tuesday is starting to look more concerning, with a significant increase in both deep-layer wind shear (as high as 30-40kts) overlapping with higher instability (possibly 2,000 J/kg SBCAPE), putting us at risk for a multicell to supercell storm mode with greater risks for damaging winds and large hail...all ahead of a shortwave and cold front. Moisture continues to look good as well. The NWS Storm Prediction Center has issued a Slight Risk (Level 2 of 5) for severe thunderstorms across most of our South Dakota counties, and a Marginal Risk (Level 1 of 5) across northeastern Wyoming. We'll definitely be keeping an eye on Tuesday's environment in the days ahead. Storm initiation currently looks to occur between 1 PM and 3 PM.

An unsettled pattern with daily chances of at least isolated showers and thunderstorms will continue through the end of the week. High temperatures by next weekend may make a run back toward the 90s.

AVIATION

(For the 12Z TAFS Through 12Z Tuesday Morning) Issued At 551 AM MDT Mon Jun 1 2026

Some morning MVFR/IFR cigs are ongoing over the southern Black Hills. Generally VFR conditions are expected at the TAF sites through the period. Showers and thunderstorms will return to the area this afternoon through the evening, especially from the Black Hills south and eastward. MVFR/IFR conditions will be possible in stronger storms.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.